Prepreg, composite molded body and method of manufacture of the composite molded body

ABSTRACT

The present invention relates to a novel composite material, that is, a prepreg, obtained by bonding a film (1) comprised of an organic polymer having substantially no melting point and having a high modulus of 700 kg/mm 3  or more and a high strength of 35 kg/mm 2  or more and a resin layer (2) and/or fiber-reinforced layer (3), a composite molded body, and a method of manufacturing a composite molded body. 
     The composite molded body obtained by bonding the film (1) and the resin layer (2) of the present invention has superior strength, excellent pliability, and large toughness in all directions. Further, the composite molded body obtained by bonding the film (1) and the fiber-reinforced resin layer (3) has both an extremely large impact resistance which could never be obtained with conventional molded bodies and also a strength and modulus greater than in the past. The molded body can be suitably used for aerospace equipment, sports goods, leisure goods, etc. making use of its light weight, corrosion resistance, and other properties in addition to the above superior proportion.

This application is a divison of application Ser. No. 08/034.171, filedFeb. 12, 1993, U.S. Pat. No. 5,597,631 which is a continuation ofapplication Ser. No. 07/582,183, now abandoned, which entirelyincorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a novel prepreg, a composite moldedbody obtained by forming the prepreg, and a method of manufacturing thesame. More particularly, the present invention relates to a prepregformed by laminating a high strength, high modulus film layer, resinlayer, and/or fiber-reinforced resin layer, a molded body obtained byforming the prepreg and having a remarkably improved impact resistanceand more isotropically improved superior strength and modulus, and,among such molded bodies, a method of manufacture of tubular or rodshaped molded bodies.

PRIOR ART

So-called fiber-reinforced resin composite materials comprised of epoxyresins, phenolic resins, and other thermosetting resins reinforced bycarbon fiber, glass fiber, aromatic polyamide fiber, etc., inparticular, carbon fiber reinforced epoxy resin composite materials,have superior specific strength and specific modulus of elasticity, soare widely used in fields demanding high strength, light weight,corrosion resistance, etc., for example, structural members of aircraft,racket frames, golf club shafts, and other sports goods, etc. On theother hand, reflecting the recent technical advances made, compositematerials are being required to offer more functions.

The long fiber reinforced composite materials such as carbon fiberreinforced epoxy resins in general are poor in toughness and as a resultare weak in impact resistance. Once they break, a sharp broken surfaceis exposed with the reinforcing fibers sticking out.

As a means for overcoming the problems related to impact resistance, acomposite material having a so-called Interleaf has been proposed inU.S. Pat. No. 3,472,730, Japanese Unexamined Patent Publication (Xokai)No. 60-63229, Japanese Unexamined Patent Publication (Kokai) No.60-231738, etc.

The earliest disclosed among these, U.S. Pat. No. 3,472,730, disclosesuse of epoxy resin containing a rubbery substance in a carbon fiberreinforced epoxy resin layer as an interleaf. However, the interleaflayer softened and became fluid at the setting and molding temperature,so there were the problems that it was difficult to form a uniform layeror that the layer would disappear.

Japanese Unexamined Patent Publication (Kokai) No. 60-63229 proposes toeliminate this problem by controlling the viscosity of the interleafresin comprised of the rubbery substance containing epoxy resin to aspecific range, while Japanese Unexamined Patent Publication (Kokai) No.60-231738 discloses art for supporting the interleaf resin layer by anonwoven fabric etc.

The basic idea of utilizing an interleaf art, as disclosed in thespecifications of the above, lies in disposing a fiber-reinforced resinlayer alternately with a resin layer having a large elongation, that is,a soft resin layer, in a laminated state and having the flexure at thetime of deformation of the composite material and any shearing energy orbreaking energy absorbed by the deformation of the interleaf resinlayer.

However, while the above known art did alleviate the problem relating toimpact resistance, there was the large problem that the strength andmodulus of the resultant composite material, that in, molded bodies, waslower than those of a molded body lacking an interleaf. Further, asatisfactory level still was not achieved with respect to the formationof a uniform interleaf resin layer.

As one of the interleaf arts, proposal was made of the use of athermoplastic resin film.

Japanese Unexamined Patent Publication (Kokai) No. 60-231738 discloses athermoplastic resin interleaf and discloses examples of use asinterleafe of resin films made of polyether imide, polyether etherketone, and polyimide. Further, in recent years, art for using as aninterleaf specific constructions of polyimide resin films treated foradhesion have been disclosed in Japanese Unexamined Patent Publication(Kokai) No. 64-129, Japanese Unexamined Patent Publication (Kokai) No.64-97246, etc.

In the art disclosed in Japanese Unexamined Patent Publication (Kokai)No. 64-129, one of the important factors with respect to the effectobtained by use of a thermoplastic resin interleaf was the suitableselection of the molecular structure of the polyimide so as to enable alarger film elongation. An understood from this, theme arts were alsobased on the technical idea of the afore-mentioned interleaf.

In other words, they were arts for improvement of the impact resistanceby introduction of a soft structure.

The use of these thermoplastic resin interleaf arts enabled theformation of a uniform interleaf resin layer. Further, while thestrength remained unavoidably lower than that of a molded body with nointerleaf in the art disclosed in Japanese Unexamined Patent Publication(Kokai) No. 60-231738, in the art disclosed in Japanese UnexaminedPatent Publication (Kokai) No. 64-129 the use of a polyimide film havinga performance enabling larger deformation made possible absorption ofthe flexural stress of the composite material under stress and as aresult made possible an increase of the resistance to breaking stress ofthe composite material and gave a composite material having an improvedbanding strength.

However, the introduction of a soft structure so as to increase thevalue of strain under a predetermined stress may be said to be reductionof the elasticity modulus, which means sacrificing the elasticitymodulus, one of the superior properties of a fiber-reinforced resincomposite material.

Another issue relating to fiber-reinforced resin is the isotrophy of themechanical performance and dimensional stability. As a method forimproving this anisotrophy, there is generally known the method ofachieving pseudoisotrophy by laminating layers changing the direction oforientation of the reinforcing fibers. With this method, however, muchtime and labor are required for cutting out the prepregs and piling themprecisely. Further, there is known the method of achieving isotrophy byrandomly orienting reinforcing fibers cut to a suitable length andmaking them into a mat then impregnating this with a matrix resin so asto make a molded body, but with this method the inherent function of thereinforcing fibers cannot be exhibited.

To resolve these problems, it may be considered to use a film havinguniform physical properties in both directions as the reinforcingmaterial, but in general film has a strength and elastic modulus over anorder smaller than fibers and therefore persons skilled in the art wouldcommonly consider that use of film as a so-called reinforcing materialwould not be appropriate.

The basic rules of composition showing the strength and elastic modulusof a composite material are given by the following equations (1) and(2):

    E.sub.o =E.sub.f ·V.sub.f +E.sub.m ·V.sub.m( 1)

    σ.sub.o =σ.sub.f ·V.sub.f +σ.sub.m ·V.sub.m                                         ( 2)

where,

E_(o) : elastic modulus of composite material

σ_(o) : strength of composite material

E_(f) : elastic modulus of reinforcing material

σ_(f) : strength of reinforcing material

E_(m) : elastic modulus of matrix resin

σ_(m) : strength of matrix material

V_(f) : volumetric content of reinforcing material in composite material

V_(m) : volumetric content of matrix resin in composite material

    (V.sub.f +V.sub.m =1)

As understood from equation (1) and equation (2), if the resin is fixed,then the physical properties of the composite material, that is, theelastic modulus and the strength, are largely governed by the physicalproperties of the reinforcing material. It will be further clearlyunderstood from this that film was not considered as-a reinforcingmaterial.

Whatever the case, it is possible to mention the above interleaf arts asexamples of the use of film as reinforcing material for compositematerials so as to improve the physical properties of molded bodies, butup until now no one has realized an art which can improve even theimpact resistance without impairing the elastic modulus and strength,the biggest features of composite materials.

DISCLOSURE OF THE INVENTION

The present invention was made in consideration of the above points andprovides a useful novel prepreg and composite material by laminating andbonding a recently developed high strength, high elastic modulus film,resin layer, and/or fiber-reinforced resin layer. That is,

The first object of the present invention is to provide a prepreg ableto give a high strength, high impact resistant composite materialcomprised of an alternately laminated and bonded high strength, highelastic modulus film and resin layer.

A second object of the present invention in to provide a prepreg able togive a high strength, high elastic modulus, high impact resistantcomposite material comprised of at least one high strength, high elasticmodulus film and at least one layer of a fiber-reinforced resin layer.

A third object of the present invention is to provide a tubular or rodshaped molded body obtained by winding and forming the above prepreg.

A fourth object of the present invention in to provide a sheet moldedbody obtained by laminating and forming the above prepreg.

A fifth object of the present invention is to provide a method formanufacturing a tubular or rod shaped molded body by winding afiber-reinforced resin prepreg, then winding outside it a prepregcomprised of a high strength, high modulus film and resin bondedtogether.

The first object of the present invention in achieved by a prepregcomprising at least one layer of a film comprising an organic polymerhaving substantially no melting point and having a tensile modulue of700 kg/mm² or more and a tensile strength of 35 kg/nm² or more and atleast one layer of a resin, said film and said resin layer being bondedto each other.

The second object of the present invention is achieved by a prepregcomprising at least one layer of a film comprising an organic polymerhaving substantially no melting point and having a tensile module of 700kg/mm² or more and a tensile strength of 35 kg/mm² or more and at leastone layer of a fiber-reinforced resin layer, said film and saidfiber-reinforced resin layer being bonded to each other.

The third object of the present invention is achieved by a tubularmolded body comprising at least one film and at least one layer of aresin layer and/or a fiber-reinforced resin layer, wherein said filmcomprises an organic polymer having substantially no melting point andhas a tensile modulus of 700 kg/mm² or more and a tensile strength of 35kg/mm² or more, said film, said resin layer, and/or said fiberreinforced resin layer being bonded to each other.

The fourth object of the present invention in achieved by a shoot moldedbody comprising at least one layer of a film and at least one layer of aresin and/or a fiber-reinforced rosin layer, wherein said film comprisean organic polymer having substantially no molting point and has atensile module of 700 kg/mm² or more and a tensile strength of 35 kg/mm²or more, said film, said resin layer, and/or said fiber-reinforced resinbeing bonded to each other.

The fifth object of the present invention is achieved by a method ofmanufacturing a tubular molded body wherein at least one layer of a filmcomprising an organic polymer having substantially no melting point andhaving a tensile modulus of 700 kg/mm² or more and a tensile strength of35 kg/mm² or more and at least one layer of a fiber-reinforced resinlayer are wound and laminated to form a tubular molded body, the tensionapplied to the film at the time of winding the film being 8 kg/mm² ormore.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 10 are sectional views showing examples of the constructionsof prepregs or molded bodies according to the present invention, whereinFIGS. 1 to 6 show examples of sheet like prepregs or molded bodies andFIGS. 7 to 10 show examples of tubular prepregs or molded bodies.

Below, the film used as the reinforcing material in the presentinvention will be referred to simply an "film".

FIG. 1 in a sectional view of an example of a plurality of layers of"film" and resin layers laminated and bonded.

FIG. 2 is a sectional view of an example of a "film" and afiber-reinforced resin layer bonded one layer at a time.

FIG. 3 is a sectional view of an example of bonding of a plurality oflayers of "film" to one side of a fiber-reinforced resin layer.

FIG. 4 is a sectional view of an example of bonding a plurality oflayers of "film" as an inner layer between two fiber-reinforced resinlayers.

FIG. 5 in a sectional view of an example of bonding a plurality oflayers of "film" to the two sides of a plurality of laminatedfiber-reinforced resin layers.

FIG. 6 is a sectional view of an example of alternate bonding of afiber-reinforced resin layer and a "film".

FIG. 7 is a sectional view of an example of a tubular shape obtained bybonding a plurality of layers of "film" and resin layers.

FIG. 8 in a sectional view of an example of a tubular shape obtained bybonding a plurality of layers of "film" to the outside of a plurality offiber-reinforced resin layers.

FIG. 9 is a sectional view of an example of a tubular shape obtained bybonding a plurality of layers of "film" to the inside and the outside ofa plurality of layers of fiber-reinforced resin layers.

FIG. 10 in a sectional view of an example of a tubular shape obtained byalternate bonding of a fiber-reinforced resin layer and a "film".

BEST MODE FOR CARRYING OUT THE INVENTION

Below, a detailed explanation will be given of the prepreg using a highperformance film, a composite material, and a method for manufacturing atubular molded body according to the present invention.

First, an explanation will be given of the requirements which should besatisfied by the "film".

The "film" of the prevent invention is comprised of an organic polymerhaving substantially no melting point. Here, "having substantially nomelting point" means that the polymer does not decompose, melt, orsoften and deform in a temperature range from room temperature to 400°C. This is a requirement so as to keep deterioration, deformation,melting, decomposition, etc. of the "film" due to heat at the time ofsetting when using it in combination with a thermosetting resin or atthe time of combining it with a high melting point thermoplastic resinand heating the latter to melt it and molding it under pressure.

As such an organic polymer, mention may be made of an aromaticpolyamide, a polyimide, polybenzimidazole, polybenzibisazole, etc. , butfrom the excellent of adhesion with a resin and the ease of realizationof a high strength and high elastic modulus, aromatic polyamides andpolyimides, in particular, aromatic polyamides, are preferable.

In the preferably used aromatic polyamide, there are those with thestructure shown by the following general formulas (I) and (II) andcopolymers of the same: ##STR1##

In the formulas, R₁, R₂, and R₃ may be selected from ##STR2## and thesehydrogen atoms may be substituted functional groups such as a halogenatom, a methyl group, an ethyl group, methyoxy group, a nitro group, ora sulfone group, and m and n represent an average degree ofpolymerization of from about 50 to about 1000.

As the polyimide, use is preferably made of a compound shown by thefollowing structural formulas, for example: ##STR3## where n is theaverage degree of polymerization and is from about 30 to about 500.

Such a "film" may be obtained by a method disclosed in Japanese ExaminedPatent Publication (Kokoku) No. 57-17886, Japanese Unexamined PatentPublication (Kokai) No. 62-194270, Japanese Unexamined PatentPublication (Kokai) No. 62-37124, Japanese Unexamined Patent Publication(Kokai) No. 62-174118, etc. in the case of an aromatic polyamide film orby a method disclosed in Japanese Unexamined Patent Publication (Kokai)No. 55-28822 etc. in the case of a polyimide film.

The "film" may include small amounts of components other than thespecific organic polymer to an extent not impairing the effect of thepresent invention, for example, may include small amounts of organicpolymers other than the above, organic low-molecular-weight compounds,inorganic compounds, etc.

As the "film", use may be made of a so-called "tensilized type" which isincreased in tensile strength and tensile modulus of elasticity in thedirection of the composite product requiring resistance to tensileforce. However, use of a "film" having isotropic properties is better inrespect to the lower directional property of the mechanical strength anddimensional stability of the resultant molded body. In the presentinvention, it is sufficient if the tensile strength and the tensilemodulus satisfy the above values in as little as one direction, butpreferably the mean values of the properties in two arbitrarily selectedorthogonal directions satisfy the above values.

In the present invention, in order to manifest a sufficient reinforcingeffect, it in preferred that the film and resin should have a largeadhesive force between them. The large adhesive force is attained by thefollowing method. The method comprises roughening the surface of thefilm or tape by making a contrivance in the film-forming process orsubjecting the formed film to a physical or chemical etching process,introducing a chemically active need to the surface by corona dischargetreatment, plasma treatment, flame treatment, chemical decomposition orthe like, carrying out an impregnation treatment before bonding by usingan epoxy compound, an isocyanate compound or a resorcinol/formalin latexmixture or by carrying out two or more of the foregoing treatments.

The thickness of the "film" of the present invention is appropriatelydetermined according to the lamination structure of the film and thefiber-reinforced resin layer in the molded product, but the thickness isgenerally 2 to 100 μm and preferably 5 to 50 μm.

If the thickness is less than 2 μm or more than 100 μm, the workabilityis poor and the ratio of the film layer in the prepreg or molded bodyobtained by lamination becomes difficult to control, so these values arenot suitable.

Next, the "film" must have a tensile strength of 35 kg/mm² or more and atensile modulus of 700 kg/mm² or more. Preferably, it has a tensilestrength of 45 kg/mm² or more and a tensile modulus of 1000 kg/mm² ormore.

An mentioned above the strength and the modulus of the compositematerial are shown in general by equations (1) and (2). Therefore, toobtain a composite material with high physical properties, it isnecessary that the "film" have high physical properties. However, noteshould be taken here of the behavior in the case of combination with afiberreinforced resin. For example, the 0° flexural strength and modulusof a carbon fiber reinforced resin layer shoot, for example, as shown inthe later mentioned Example 7, are 128 kg/mm and 6900 kg/nm², socompared with these, the value of the modulus of the above "film" isstill low. Therefore, in particular, the modulus falls proportionallywith the volumetric content of the film layer introduced and with filmoutside the range of the present invention, that is, film with a lowmodulus of loss than 700 kg/mm², that phenomenon appears even more(Comparative Example 5). However, very surprisingly, in the presentinvention, as shown by Example 12, despite the ratio of the carbon fiberreinforced resin layer (hereinafter referred to as the CF resin layer)being reduced, no decline is seen (Example 8). If converted by the ratioof the CF resin layer, the flexural strength and the modulus are bothimproved over 10 percent, it may be said.

The same is true with a 90° flexural modulus. Further, the flexuralstrength increases along with the increase of the film strength, butwhen the strength of the film meets the requirements of the presentinvention, that value exhibits the effect equal to or better than theso-called angle play on the CR resin layer, as will be understood fromthe peripheral flexural strength of the tubular molded body (forexample, Example 16 and Comparative Example 2).

In general, in a polymer material, the physical properties change alongwith the degree of orientation of the molecular chains and the greaterthe orientation and the modulus, the less the elongation at break. Theelongation of the film used in the present invention in face is muchsmaller than in a film used in the aforementioned interleaf arts.

However, both the Izod impact strength and the drop impact absorptionenergy, indicators of the impact resistance, are values never beforeachieved compared with these arts, it should be specially mentioned.

That is, when the "film" meets the requirements of the presentinvention, a composite material in obtained which is superior in all ofthe strength, modulus, and impact resistance--completely different fromthe conventional, known interleaf arts based on the high elongation,soft structure in both technical idea and resultant effects, it must beunderstood.

Next, an explanation will be made of the resin and the fiber-reinforcedresin used in the present invention.

The thermosetting resin used in the present invention is notparticularly critical. For example, the thermosetting resin is selectedfrom an epoxy resin, a phenolic resin, a polyimide resin and a polyesterresin. An ultraviolet absorber, a flame retardant, an antioxidant, alubricant, a colorant, a heat stabilizer, an aging preventing agent, areinforcing staple fiber, a reinforcing powder or particle, a moldingchemical,a thermoplasticizer, an elastomer, a rubbery substance, andother usual resin additives may be added.

The thermoplastic resins used in the present invention are notparticularly limited and may be for example polyolefins, polyesters,polyamides, polyacrylates, polycarbonates, etc., but from the viewpointof the heat resistance of the obtained molded body or the range ofunable temperature etc., preferably use is made of a so-calledsuprengineering plastic. As examples of these, there are polysulfone,polyamide imides, polyether imides, polyether ketones, polyether otherketones, polyether sulfones, and polyphenylene sulfide.

At the time of use of those resins, the resins may be used in the formof a solution or dispersion using a suitable solvent or may be usedheated and malted. Further, so long as it can be formed into a film, itmay be used laminated as is in the film state. In that case, it iseffective to improve the adhesion ability of the film by surfacetreatment by a known method, for example, the corona dischargetreatment, plasma treatment, and the like.

As the reinforcing fiber used in the present invention, there can bementioned glass fiber, carbon fiber, aromatic polyamide fiber,polybenzimidazole fiber, polybenzothiazole fiber and metal-clad fibersthereof, for example, a nickel-plated carbon fiber. Furthermore,inorganic fibers such as an alumina fiber and a silicon carbide fibercan be used. Two or more of these fibers can be used in combination.

The fiber can be used in the form of a unidirectionally fiber-arrangedsheet (UD sheet) or a woven fabric or knitted fabric. In the fieldswhere isotropic mechanical properties are required, a nonwoven fabric ora mat comprising fiber cut in an appropriate length and orientedrandomly can be used.

The fiber-reinforced resin layer may be made by a known art, forexample, the method of impregnating a solution or dispersion of theresin in the above reinforced fiber UD shoot, woven or knitted fabric,nonwoven fabric, or mat, the method of impregnating a malted resin, orthe method of laminating a rosin previously formed in a film shape underheating for impregnation.

The ratio of the reinforcing fibers and the resin is suitably selectedaccording to the shape of the reinforced fiber sheet and the type of thereinforcing fibers, but usually a volumetric content of reinforcingfibers in the region of 40 to 70 percent is preferably used.

The prepreg of the present invention in comprised of the above-mentioned"film" and resin and/or fiberreinforced resin layer.

The first embodiment lies in a prepreg comprising at least one layer ofa film comprising an organic polymer having substantially no meltingpoint and having a tensile modulus of 700 kg/mm² or more and a tensilestrength of 35 kg/mm² or more and at least one layer of a resin, saidfilm and said resin layer being bonded to each other.

The "film" itself has almost no heat fusibility or heat adhesivity sothe prepreg, as shown in FIG. 1 and FIG. 7, has a structure of the"film" and the resin alternately laminated. The prepreg is notparticularly limited and may have the "film" and the resin bonded oneshoot or one layer at a time or bonded in a plurality of sheets orplurality of layers at a time and may be shaped an a thin sheet, aplate, tube, etc. Further, w

The second embodiment of the prepreg lies in a prepreg comprising atleast one layer of a film comprising an organic polymer havingsubstantially no melting point and having a tensile module of 700 kg/mm²or more and a tensile strength of 35 kg/mm² or more and at least onelayer of a fiber-reinforced resin layer, said film and saidfiber-reinforced resin layer being bonded to each other.

The prepreg of the second embodiment, an shown in FIGS. 2 to 6 or FIGS.8 to 10, may have various lamination structures. That in, the prepreg ofthe present invention includes the simplest construction of a prepregwhere the "film" and fiber-reinforced resin layer are bonded one sheetor one layer at a time (FIG. 2), a prepreg where a plurality of sheetsof "film" are bonded to one side of a fiber-reinforced resin layer (FIG.3 and FIG. 9), a prepreg where the "film" layer in bonded to the inside(inner layer) of a fiber-reinforced resin layer (FIG. 4), a prepregwhere a "film" layer is bonded to both sides of a fiber-reinforced resinlayer (FIG. 5 and FIG. 9), a prepreg where a fiber-reinforced resinlayer and a "film" are alternately bonded (FIG. 6 and FIG. 10) and,further, even a prepreg of a combination of these structures. Theprepreg of the present invention may be used in those variousconstructions and give extremely superior effects as shown in theexamples. In this regard, the present invention is a set apart from theabove-mentioned interleaf art which was useful only in the came ofalternate lamination and enables an extremely wide range of application.

Note that FIG. 7 to FIG. 10 show, for convenience sake, constructionswhere the layers, that is, the "film", resin layer, and/orfiber-reinforced resin layer, are laminated concentrically. However, asa tubular lamination structure, in many cases, use in made of alamination structure where the layers are wound spirally in singlelayers or a plurality of layers.

In the case of bonding a plurality of shoots of "film" as a layer, useis made of "films" bonded together by a resin. As the resin, use may bemade of a resin different from the matrix resin of the fiber reinforcedresin, but in view of the advantage of enabling molding under the sameconditions, it is preferable to use the same resin.

When the matrix resin of the fiber-reinforced resin is a thermosettingresin, the prepreg is the state where the resin is bonded in an uncuredor semicured state. For thermoplastic resins, the prepreg is the stateable to be used as a material for obtaining the final product.

In a prepreg obtained by bonding a "film" and fiber-reinforced resinlayer, the volumetric content of the film in the molded body as a wholeshould be 5 to 50 percent, preferably 10 to 30 percent. If less than 5percent, one can only obtain a molded body with unsatisfactory effect ofimprovement of the impact resistance, and conversely if over 50 percent,there is a large drop in the rigidity of the molded body.

The molded body of the present invention may be a tubular molded bodycomprising at least one film and at least one layer of a resin layerand/or a fiberreinforced resin layer, wherein said film comprises anorganic polymer having substantially no melting point and has a tonsilsmodulus of 700 kg/mm² or more and a tensile strength of 35 kg/mm² ormore, said film, said resin layer, and/or said fiber reinforced resinlayer being bonded to each other or may be a plate molded bodycomprising at least one layer of a film and at least one layer of aresin and/or a fiber-reinforced rosin layer, wherein said film comprisesan organic polymer having substantially no melting point and has atensile module of 700 kg/mm² or more and a tensile strength of 35 kg/mm²or more, said film, said resin layer, and/or said fiber-reinforced resinbeing bonded to each other.

The lamination structure of a molded body comprised of a "film", resinlayer, and/or fiber-reinforced resin layer is the same as that of thepropreg. That is, in a molded body obtained by bonding a "film" and aresin layer, there is the structure of the "film" and resin layer bondedalternately, and in a molded body obtained by bonding a "film" andfiberreinforced resin layer, there are, for example the variousstructures as shown in FIG. 2 to FIG. 6 and FIG. 8 to FIG. 10.

The molded body is distinguished from a prepreg in being a final productformed into a desired shape by curing of the resin when the matrix resinof the resin layer or the fiber-reinforced resin layer is thermosettingand in being a final product given a desired shape at a temperatureabove the melting point of the resin when the resin is a thermoplasticone.

The tubular body of the present invention may have variouscross-sectional shapes, for example, a true circle, ellipse, orpolyhedron and includes many forms such as a straight tube or curvedtube with a constant diameter, a tapered tube, or a tube with apartially different diameter or thickness. As a special example, thereis included a solid rod shape obtained by using a resin orfiber-reinforced resin rod etc. as a mold and bonding the mold as wellto make the final product.

The plate body of the present invention includes, in addition to flatplates, plates with an L-shaped, H-shaped, or other bent sectional shapeand also includes a shape bend overall or partially as with a reflectingplate of a parabolic antenna.

Also included in the molded bodies of the present invention are moldedbodies of a tubular form made by the so-called sheet rolling methodetc., plate molded bodies obtained by laminating closely narrowly slittape-like prepregs, and tubular molded bodies obtained by winding narrowprepregs in parallel or at an angle with each other.

Next, an explanation will be made of the method of manufacture of theprepregs and the molded bodies of the present invention. The prepreqsand molded bodies of the present invention may be manufactured byvarious methods.

(1) Prepregs Obtained by Laminating and Bonding Film and Resin Layers

a. "Film"/thermosetting resin prepregs

It is possible to manufacture a so-called B stage film-like prepreghaving the simplest structure by coating at least one side of the filmof the present invention with a melt or solution of a thermosettingresin by a doctor knife etc. and, when necessary, heating the same, soas to laminate one layer at a time of film and resin layer. This prepregmay be further alit for use as a tape-like prepreg of a width of lessthan 50 mm or a sheet-like prepreg of a width of 500 mm or 1000 mm.Further, use may be made of a single layer of the prepreg as it is, butit is also possible to laminate a plurality of prepregs to made aprepreg with a suitable thickness. Also, it is possible to make atubular prepreg by winding a single layer of prepreg several timesaround a mold pretreated to facilitate mold release, then pulling outthe mold.

Since a "film" with extremely high modulus and stiffness is used, theresultant prepreg is easy to handle and enables easy so-called handlayup.

b. "Film"/thermoplastic resin prepregs

The prepreg can be made by, in the same way as in a, for example, by themethod of coating a solution or malt of the thermoplastic resin on the"film". Further, by heat-pressing the "film" after the thermoplasticresin is formed into a film shape from the malt or solution state, it ispossible to make a prepreg with the "film" and thermoplastic resin layerbonded one layer at a time.

Several layers of the above prepreg may be laminated and heat-pressed tomake a prepreg comprised of a plurality of layers of "film" andthermoplastic resin layers bonded together. Note that at that time, the"film" and the thermoplastic resin layer may be alternately laminated ina plurality of sheets and layers and then, for example, subjected toheat pressing etc. to bond the plurality of sheets of film and thethermoplastic resin film.

(2) Prepregs Obtained by Laminating and Bonding Film andFiber-Reinforced Resin Layers

a. "Film"/fiber-reinforced thermosetting resin preproge

It is possible to manufacture a prepreg by pressing together a B-stagefiber-reinforced thermosetting resin prepreg and the "film". Thisprepreg may be made by the method of coating the film in advance withthe thermosetting resin in the molten state or coating it in the form ofa solution or mixture using a suitable solvent, then heating to expelthe solvent and pressing this with a reinforcing fiber sheet under heat.

By laminating a plurality of theme preproge, for example, using alaminator, it is possible to make a prepreg with a large thickness.

Further, by successively laminating prepregs obtained by bonding a resinto one side of a "film" and a fiber-reinforced thermosetting resinprepreg by, for example, a laminator, it is possible to make a prepreghaving various lamination structures. For example, by winding them abouta stainless steel mold, it is possible to make a tubular prepreg.

A prepreg obtained by bonding a "film" and fiber-reinforcedthermosetting resin in backed by a film with a large modulus andstiffness, so is extremely easy to handle. In particular, by bondingwith a so-called UD prepreg with fibers unidirectionally disposed, theproblems of cracking or opening up along the fiber direction duringhandling can be eliminated and easy hand layup is possible.

b. "Film"/thermoplastic resin prepregs

For example, the prepregs can be made by the method of heat fusing afiber-reinforced thermoplastic rosin shout and "film" at a temperatureabove the melting point of the resin or heating and pressing togetherthe "film" and a thermoplastic resin formed in advance in a film shapeand a reinforcing fiber sheet at a temperature above the melting pointof the resin.

By using a prepreg obtained by bonding a single shoot of "film" and asingle thermoplastic resin layer and a fiber-reinforced thermoplasticresin prepreg and laminating and bonding the same using, for example, alaminator, it is possible to make prepregs with various laminationstructures.

(3) Tubular Molded Bodies

A tubular molded body can be obtained winding a prepreg shown in (1) and(2) around a rod shaped mold made of stainless stool with varioussectional shapes and heating for thermosetting or heating for melting.

Further, it may be made by filling a prepreg previously prepared in acylindrical shape into a mold with a desired shape and heating underpressure from the inside.

Also, by using a fiber-reinforced resin rod formed by drawing as themold for winding the prepreg and setting the resin to make an integralbody, a solid rod-shaped molded body may be obtained.

Further, the tubular molded body may be made by winding afiber-reinforced resin layer on a stainless steel mold of varioussectional shapes, then winding on top in a spiral fashion and bondingthereto a tape-like prepreg obtained by bonding a resin to at least oneside of a "film", then heating.

In a molding method using this so-called taping, during the taping, thetension applied to the tape-like prepreg is extremely important toobtain a good quality molded body. It is essential that the tension bekept at 9 kg/mm² per sectional area of the "film". Preferably it ismaintained at 10 kg/mm² or more, more preferably 12 kg/mm² or more.

When wound with a tension of loss than 8 kg/mm² the laminated layers arenot closely attached, so interlaminar separation tends to occur and onlya molded body with insufficient physical properties can be obtained.Further, wrinkles easily occur in the component elements in the moldedbody, which wrinkles cause a reduction of the physical properties andare also detrimental to the outer appearance.

Winding and bonding the film at a high tension not only enables thefiber-reinforced resin layer and the film to be closely bonded duringmolding and spreads the matrix resin uniformly throughout the wholearticle, but also is believed to have the effect of suppressing changesin shape of the molded body due to imparted loads due to theconstraining force based on the residual stress remaining in the filmeven after molding.

The above manufacturing method represents the fifth invention of thepresent invention. To enable molding meeting the above requirements tobe performed stably, it is important that the film be high in strengthand high in modulus.

(4) Plate Molded Bodies

It is possible to obtain a plate-shaped molded body by filling theprepregs shown in (1) and (2) into a mold of a desired shape and curingthem under pressure at the curing temperature of the thermosetting resinor melting the same at a temperature above the melting point of athermoplastic rosin. By suitably selecting the shape of the mold and themethod of lamination of the prepregs, it is possible to make not only aso-called flat plate, but also a molded body having a bent shape, suchas an L-shaped or H-shaped section, or a partially or wholly curvedshape. These are included in the scope of plate molded bodies.

Further, at the time of molding, it is possible to use the method ofdirectly laminating and filling "film", resin film, and/or reinforcingfiber sheets into a mold and heating and pressing the same in additionto once using a prepreg.

As mentioned above, the molded body comprised of a composite materialobtained based on the present invention has extremely superior physicalproperties never obtained before now, such as strength, modulus, andimpact resistance, and further has the features of superior absorptionof vibration, light weight, corrosion resistance, and easy of working.Making use of these features, it can be widely used for golf clubshafts, fishing rods, ski poles, tennis and badminton racket frames, andother sports and leisure goods and also bicycle frames, outer panels andstructural members of automobiles, ships, etc., and further evenaerospace applications such as rocket motor cases, aircraft structuralmembers, space station structural members, etc.

Next, an explanation will be given of the methods of measurement of thephysical properties of the "film" and the molded bodies in the presentinvention.

a. Tensile Strength and Elongation and Modulus of Film.

A fixed speed stretch type strength and elongation measuring apparatus(Autograph Model DSS-500 made by Shimadsu Seisakusho) was used. A filmsample whose thickness was measured by a dial gauge was cut into a 100mm×10 rectangular shape. A load-strain curve was drawn with an initialclamping length of 30 mm and a tensile speed of 30 mm/min, and thetensile strength TS (kg/mm²), elongation at break TE (%), and tensilemodulus M_(i) (kg/mm²) were found from the same.

TS=P/10t

TE=l/30×100

M_(i) =P_(i) /10t×30/l_(i)

where,

P: tensile load at break (kg)

t: film thickness (mm)

l: tensile strain at break (mm)

P_(i) : load (kg) at strain l_(i) at straight line portion ofload-strain curve

b. Tensile Strength and Elongation and Modulus of Plate Molded Body

A sample of a size of 10 m width and 150 mm length was cut out from aplate obtained by laminating "film" and resin, the two ends were adheredto tapered glass fiber reinforced resin tabs (length 50 mm), and theresult used as a test piece.

The test piece was met in a Shimadzu Seisakusho universal tester(tradename: Autograph Model AG-10) at a clamping interval of 50 mm,stretched at a tensile speed of 0.5 mm/min, and the tensile strengthσ_(T) (kg/mm²), breaking strain e_(T) (%), and tensile modulus E_(T)(kg/mm²).

σ_(T) =P/Wt

e_(T) =l/50×100

E_(T) =P_(i) /Wt·50/l_(i)

where,

P: tensile load at break (kg)

t: test piece thickness (m)

W: width of test piece (m)

l: tensile strain at break (mm)

P_(i) : load (kg) at strain l_(i) at straight line portion ofload-strain curve

c. Axial Compression Strength

A test piece having a length of 13 mm was cut out from a tubular moldedbody and was compressed in the longitudinal direction at a compressingspeed of 1 mm/min by using a Shimadzu Seisakusho universal tester(Autograph Model AG-10) and the maximum breaking strength was measured.The axial compression strength was calculated according to the followingformula:

    σ.sub.1 =4P/π(d.sub.2.sup.2 -d.sub.1.sup.2)

where,

σ₁ : axial compression strength (kg/mm²)

d_(l) : inner diameter of the test piece (mm)

d₂ : outer diameter of the test piece (mm)

P: maximum breaking strength (kg)

d. Face Compression Strength

A test piece having a length of 17 mm was cut out from a tubular moldedbody and was compressed in the radial direction at a compressing speedof 1 mm/min. The maximum breaking strength was measured. The facecompression strength was calculated according to the following formula:

    σ.sub.2 =3P/πLd.sub.1 ×(d.sub.2 +d.sub.1).sup.2 /(d.sub.2 =D.sub.1).sup.2

where,

σ₂ : face compression strength (kg/mm²)

L: length (mm) of the test piece

Other symbols are as defined in the method of measurement of the axialcompression strength.

e. Izod Impact-Absorbing Energy

A test piece having a length of 64 cm was cut out from the tubularmolded body and directly used for the test. The test was carried out ata hammer weight of 3.974 kg and a lift-up angle of 135° by a ShimadzuSeisakuaho Izod impact tooter. The impact-absorbing energy wascalculated according to the following formulas:

    E=4WR(cos β-cos 135°)/π(d.sub.2.sup.2 -d.sub.1.sup.2)

where,

E: Izod impact-absorbing energy (kg·cm/cm²)

W: weight (3.874 kg) of the hammer

R: distance (22.41 cm) between the axis of the hammer and the center ofgravity thereof

β: angle (°) at which the hammer, which has broken the sample, swings upon the opposite side.

f. Flexural Strength and Flexural Modulus of Tubular Body

A test piece having a length of 120 mm was cut out and tested by using aShimadzu Seisakusho universal tester (Autograph Model AG-10) at abanding speed of 3 mm/min while adjusting the distance between fulcra to100 mm. The top end of a compressing wedge was of R5 and the top and ofthe fulcrum was of R2. The flexural strength of, and flexural modulusEf_(p) were calculated from the obtained load-deflection curve.

    σf.sub.p =8·L·d.sub.2 ·P/π(d.sub.2.sup.4 =d.sub.1.sup.4)

where,

σf_(p) : flexural strength (kg/mm²)

d₁ : inner diameter of the test piece (mm)

d₂ : outer diameter of the test piece (mm)

L: distance between fulcra (mm)

P: flexural load at break (kg)

    Ef.sub.p =4·L.sup.3 /3π(d.sub.2.sup.4 =d.sub.1.sup.4)·F/y

where,

Ef_(p) : flexural modulus (kg/mm²)

F/y: gradient (kg/mm) of the straight portion of the load-deflectioncurve.

g. Flexural Strength and Flexural Modulus of Plate

A test piece having a width of 25 mm and a length of 50 mm was cut outfrom a laminated board and was tested using a Shimadsu Seisakushouniversal tester (Autograph Model AG-10) at a bending speed of 2 mm/minwhile adjusting the distance between fulcra to 35 mm. The top end of acompressing wedge was of R5 and the top end of the fulcrum was of R2.The flexural strength (σf) and flexural modulus (Ef) were calculatedfrom the obtained load-deflection curve according to the followingformula:

    σf=3PL/2Wh.sup.2

where,

σf: flexural strength (kg/mm²)

W: width (mm) of the test piece

h: thickness (mm) of the test piece

L: distance (mm) between fulcra

P: maximum breaking load (kg)

    Ef=L.sup.3 /4Wh.sup.3 ·F/y

where,

Ef: flexural modulus (kg/mm²)

F/y: gradient (kg/mm) of the straight portion of the load-deflectioncurve.

h. Drop-Impact Test

A test piece having a size of 100 mm×100 mm was cut out from a laminatedboard and tested using a drop impact tester supplied by Rheometrix underconditions of a load of 30 kg, a dropping height of 20 cm and a testspeed of 2 m/sec. The total absorption energy was determined from theobtained absorption energy curve.

Below, the present invention will be explained in further detail usingexamples.

First, an explanation will be given of the method of manufacturing thearomatic polyamide film used in the examples.

An aromatic polyamide film was prepared usingpoly-p-phenyleneterephthalamide (hereinafter referred to as PPTA). ThePPTA was dissolved in a 98 percent concentrated sulfuric acid at aconcentration of 0.5 g/100 ml. The logarithmic viscosity number was 5.5at 30° C. The PPTA was dissolved in 99.5 percent sulfuric acid to give apolymer concentration of 12 percent and to obtain an opticallyanisotropic dope. The dope was deacrated in vacuo, filtered, passedthrough a gear pump, extruded from a alit die, cast on a belt oftantalum having a polished mirror surface, passed through an airatmosphere, maintained at a relative humidity of about 40 percent and atemperature of about 90° C. to render the cast dope optically isotropic,and introduced into a 30 percent aqueous solution of sulfuric acidmaintained at 20° C. together with the belt to coagulate the cast dope.

Next, the coagulated film was peeled from the belt, neutralized with anaqueous solution of sodium hydroxide and washed with water. The washedfilm was drawn by a roller in the longitudinal direction (MD direction)without drying. Then, the film was drawn by a tenter in the lateraldirection (TD direction), then dried at 200° C. while keeping the lengthconstant and heat-treated at 300° C. while keeping the length constant,giving a PPTA film of a thickness of 20 μm (film A) and a PPTA film of athickness of 10 μm (film B).

The physical properties of the film A and the film B are shown in Table1 together with the physical properties of films used in the otherexamples and comparative examples, i.e., Upilex-20S (phonetic) of Ubeindustry, Upilex-20R (phonetic), Capton 100H of E.I. Dupont Nemours, anda 20 μm polyethylene terephthalate (hereinafter referred to as PET) filmobtained by malt film formation using a T-die.

Films A and B and Upilex-20S were films suitable for the presentinvention, while the others were unsuitable films.

                                      TABLE 1                                     __________________________________________________________________________    Physical Properties of Various Films                                                                   Melting point                                                                 or                                                   Film name                                                                           Tensile                                                                             Tensile      decomposition                                        (thickness:                                                                         strength                                                                            modulus                                                                             Elongation at                                                                        temperature                                          μm)                                                                              (kg/mm.sup.2)                                                                       (kg/mm.sup.2)                                                                       break (%)                                                                            (°C.)                                                                         Remarks                                       __________________________________________________________________________    Film A (20)                                                                         43.9  1290  23.5   400 or more                                          Film B (10)                                                                         44.8  1350  25.6   400 or more                                          Upilex 20S                                                                          42.2  810   34.2   400 or more                                                                          Ube Industry                                  (20)                                                                          Upilex 20R                                                                          34.0  380   145.1  400 or more                                                                          "                                             (20)                                                                          Capton 100H                                                                         31.0  300   92.7   400 or more                                                                          E. I. Dupont                                  (25)                            Nemours                                       PET (20)                                                                            25.1  400   130.3  270                                                  __________________________________________________________________________

First, examples will be shown regarding the prepregs and molded bodiesobtainable by bonding a "film" and resin (Examples 1 to 5).

EXAMPLE 1

One surface of the film A was coated with an epoxy resin #7714 made byKasei Fiberlight Co. (mixture of methyl ethyl ketone, solid content of70 percent by weight) using a coater of Yuri Roll Kikai Co. by the commadirect method. This was heated at 100° C. for 15 minutes to make thefilm A/epoxy prepreg. The thickness of the epoxy resin was about 10 μm.

The above prepreg was laminated by a stainless steel roll coated withTeflon and having a diameter of 100 μm, under pressure by a nip roll,until 35 prepregs were wound up. A short book like laminated prepreg wasobtained by cutting open one location of the obtained wound body alongthe axial line.

This was placed in a rectangular flat mold and hold there at 120° C. and0.5 kg/mm² for 15 minutes, then heated and pressed at 150° C. and 50kg/m² for 60 minutes. The mold was cooled to room temperature, then themolded body was taken out, to obtain a laminated board of a thickness of1 mm.

The physical properties of the resultant laminated board are shown inTable 2.

In the same way as the later mentioned Example 4, the molded bodyobtained by bonding the "film" and the resin of the present inventionhas an extremely high strength, it will be understood. That is, ingeneral, the physical proportion of resin materials of the type referredto an engineering plastics are the values of the extent shown below:

Tensile strength: 10 to 20 kg/mm²

Flexural strength: 8 to 20 kg/mm²

Flexural modulus: 300 to 500 kg/mm²

Even in the case of reinforcement by glass staple fibers, the values areabout the below:

Tensile strength: 15 to 20 kg/mm²

Flexural strength: 15 to 30 kg/mm²

Flexural modulus: 700 to 1100 kg/mm²

Comparing these values with the values in Table 2, the superiority ofthe strength of the molded body of the present invention will be clear.

On the other hand, the molded body has a large strain compared with thelater mentioned fiber-reinforced resin. As a result, the molded bodyobtained by bonding the "film" and resin of the present Invention is anextremely tough new molded body never before seen.

EXAMPLE 2

A stainless steel rod having a diameter of 10 mm was used as the mold.The epoxy resin-coated prepreg was supplied into the mold in thevertical direction and was wound and laminated 35 turns. This waswrapped with a polyethylene terephthalate tape (referred to as PET tape)having a width of 15 mm and a thickness of 30 μm which had beensubjected to a releasing treatment, and curing was carried out for 2hours in a hot air-circulating heater maintained at 140° C. The curedmolded body was taken out and the PET tape was removed, and the mold wasdrawn out to obtain a tubular molded body having an inner diameter of 10mm and an outer diameter of 12 mm.

EXAMPLE 3

The propreg obtained body bonding epoxy resin to the film A, obtained inExample 1, was slit into a tape-like prepreg having a width of 15 mm.

By using a taping machine supplied by Shimano Kogyo, the tape-likeprepreg was wound at a pitch of 3 mm on a stainless steel rod having adiameter of 10 mm while feeding it in the longitudinal direction. Then,the winding direction was reversed and the tape was similarly wound.This operation was repeated 7 times to obtain a spirally laminatedmolded body. In the same manner as described in Example 2, the moldedbody was wrapped with the PET tape, curing was carried out, the PET tapewas removed and the mold was drawn out to obtain a pipe-shaped compositematerial having an inner diameter of 10 mm and an outer diameter of 12mm.

Comparative Example 1

Prepregs obtained by bonding epoxy rosin were made in the same way asExample 1 using Capton 100H (phonetic) and PET film as the film. The twoprepregs were wound and laminated in the same way as in Example 2 tomake tubular molded bodies of an inner diameter of 10 mm and an outerdiameter of about 12 mm

EXAMPLE 4

Polyphenylene sulfide (hereinafter referred to as PPS) supplied byToray-Phillips was heated and melted at 340° C., extruded from a alitdie, and cast in the form of a film on film A running on a roll belowthe die. Then, the laminated films were pressed between a pair of niprolls disposed Just downstream to make a prepreg of bonded "film" andPPS of a total thickness of 30 μm.

The prepreg was cut in a short book form and set in 35 layers in arectangular flat mold. These were heated and pressed for 10 minutesunder conditions of 350° C. and 20 kg/cm² by a hot-press apparatus. Thepressed assembly was cooled to 50° C. to obtain a laminated board havinga thickness of 1 mm.

EXAMPLE 5

The prepreg obtained in Example 4 was slit into a tape having a width of10 mm to obtain a tape-like prepreg. This tape-like prepreg was fed at apitch of 2.5 mm to a rod-shaped stainless steel mold having a diameterof 10 mm by using a taping machine and wound at a tension of 10 kg. Thisoperation was repeated 8 times for a lamination corresponding to 32layers of the film A. The winding-initiating and winding-terminatingends were fixed by a stainless steel collar, and the assembly was heatedfor 5 minutes in an oven maintained at 350° C. This was cooled to roomtemperature, then the mold was drawn out to obtain a laminated tubehaving an inner diameter of 10 mm and an outer diameter of about 12 mm.

Comparative Example 2 Carbon Fiber Reinforced Epoxy Resin Pipe (CF/EpoxyPipe)

A CF/epoxy pipe was formed as follows to clarify the position of thephysical properties of the molded body obtained from a prepregcomprising the "film" and resin layer bonded together.

A CF/epoxy UD prepreg (tradename: Fiberdux (phonetic) (0.2 mm thick))supplied by Asahi Composite was wound in five layers around a stainlesssteel rod mold having a diameter of 10 mm at an angle with thelongitudinal direction of the mold of 0° and 25°. On top of this waswrapped PET tape treated for release, then the assembly was heated andcured in an oven at 150° C. This was allowed to cool to roomtemperature, then the mold was withdrawn to make two types of laminatepipes with inner diameters of 10 mm and outer diameters of about 12 mm.

Comparative Example 3 Metal Pipe

To clarify the position of the physical properties of the molded bodyobtained from a prepreg comprising the "film" and resin bonded together,pipes of aluminum and iron of an inner diameter of 10 mm and outerdiameter of 12 mm were prepared and the physical properties thereofevaluated.

The physical properties of the laminated board of Examples 1 and 4 areshown in Table 2.

In the case of use of a thermoplastic resin, there are the advantages ofsimplification of the molding operation and the higher toughness due tothe increase of the strain of the molded body.

The results of Examples 2, 3, and 5 and Comparative Examples 1 to 3 areshown in Table 3.

As may be foreseen from the physical properties of the board, thephysical proportion of the tubular body of the present invention arecomparable to the physical properties of a CF·UD prepreg angle-plylaminated. It is suggested that reinforcement is realized in directionsother than the direction of fiber orientation and that more isotropicphysical properties can be imparted.

As opposed to this, with a soft film not suited to the presentinvention, only physical properties obtainable with the conventionalgeneral use rosin materials could be obtained.

                  TABLE 2                                                         ______________________________________                                        Physical Properties of PPTA Film/Resin Laminated Board                                       Example 1    Example 5                                                        20 μm PPTA film                                                                         .sup.2 0 μm PPTA film                          Physical properties                                                                          Epoxy resin  PPS                                               ______________________________________                                        Tensile strength (kg/mm.sup.2)                                                               41.6         43.7                                              Specific strength of same                                                                    29.7         31.4                                              Tensile modulus (kg/mm.sup.2)                                                                1160         1180                                              Specific modulus of same                                                                     830          850                                               Tensile strain at break (%)                                                                  28.2         31.4                                              Flexural strength (kg/mm.sup.2)                                                              34.6         37.2                                              Specific strength of same                                                                    24.7         26.8                                              Flexural modulus (kg/mm.sup.2)                                                               370          380                                               Specific modulus of same                                                                     260          270                                               ______________________________________                                    

                                      TABLE 3                                     __________________________________________________________________________    Physical Properties of Tubular Bodies of Various Materials                                                 Comp. Ex. 2                                                                   CF/ CF/                                                   Ex. 2                                                                             Ex. 3                                                                             Comp. Ex. 1                                                                           Ex. 5                                                                             epoxy                                                                             epoxy                                                 20 μm                                                                          20 μm                                                                          Cap-                                                                              20 μm                                                                          20 μm                                                                          UD  UD                                                    PPTA                                                                              PPTA                                                                              ton PET PPTA                                                                              pre-                                                                              pre-                                                                              Comp. Ex. 3                                       film/                                                                             film/                                                                             100H/                                                                             film/                                                                             film/                                                                             preg                                                                              preg                                                                              Alum-                                    Physical properties                                                                    epoxy                                                                             epoxy                                                                             epoxy                                                                             epoxy                                                                             PPS (0°)                                                                       (25°)                                                                      inum                                                                              Iron                                 __________________________________________________________________________    Axial compressive                                                                      15.8                                                                              15.5                                                                              11.6                                                                              10.7                                                                              14.9                                                                              54.9                                                                              21.1                                                                              12.2                                                                              64.7                                 strength (kg/mm.sup.2)                                                        Specific strength                                                                      11.4                                                                              11.1                                                                              8.3 7.8 10.8                                                                              34.2                                                                              13.4                                                                              4.7 8.6                                  of same                                                                       Face compressive                                                                       41.9                                                                              42.6                                                                              16.6                                                                              15.7                                                                              41.0                                                                              9.6 35.2                                                                              29.2                                                                              50.3                                 strength (kg/mm.sup.2)                                                        Specific strength                                                                      30.1                                                                              30.6                                                                              11.9                                                                              11.4                                                                              29.5                                                                              6.0 22.3                                                                              11.2                                                                              6.7                                  of same                                                                       3-point flexural                                                                       17.4                                                                              18.1                                                                              12.7                                                                              10.8                                                                              18.8                                                                              10.2                                                                              17.3                                         strength (kg/mm.sup.2)                                                        Specific strength                                                                      12.5                                                                              13.0                                                                              9.1 7.8 13.6                                                                              6.4 10.9                                         of same                                                                       3-point flexural                                                                       650 620 410 370 570 530 1360                                         modulus (kg/mm.sup.2)                                                         Specific modulus                                                                       470 450 290 270 410 310 860                                          of same                                                                       Izod impact strength                                                                   311 302 175 94  324 154 251                                          (kg · cm/cm.sup.2)                                                   __________________________________________________________________________

Next, an explanation will be given of prepregs obtained by bonding"film" and fiber-reinforced resin and the plate molded bodies obtainableby molding the same, based on examples (Examples 6 to 12).

EXAMPLE 6

A prepreg was made by pressing the film A onto one surface of theCF/epoxy UD prepreg (Fiberdux (phonetic) made by Asahi Composite) usedin Comparative Example 2 using a laminate roll at conditions of atemperature of 90° C. and a line pressure of 6 kg.

In general, such a UD prepreg is comprised of a sheet of a large numberof CF yarns arranged unidirectionally impregnated with an uncured epoxyresin, so when cutting the prepreg to a desired size or laminating it,there is a tendency for spaces to appear between the CR yarns during theoperation of peeling off the release paper on which the prepreg isplaced, thus requiring careful handling.

As opposed to this, the prepreg of the present invention has stifffibers closely adhered and can be handled as an integral molded body asis, so there is no appearance of spaces between fibers forming the UDprepreg and the handling becomes extremely easy.

Nine layers of prepregs were laminated so that the carbon fibers were inthe same direction. The vacuum bag autoclave method was used to obtain alaminated board at a temperature of 150° C., a pressure of 7 kg/cm²,requiring 2 hours time. The thickness of the resultant laminate boardwas about 2 mm and the board had a structure of film layers and CF/epoxylayers alternately laminated.

EXAMPLE 7 AND COMPARATIVE EXAMPLE 4

Laminate boards were made by molding under the same conditions asExample 6 using as the film Upilex-20S (phonetic) (Example 7) and Capton100H (phonetic) (Comparative Example 4).

EXAMPLE 8

The film A was coated with an epoxy resin #7714 made by Kasei FiberlightCo. using a coater of Yuri Roll Kikai Co. by the direct gravure method.This was heated at 100° C. for 15 minutes to make the film A/epoxyprepreg.

First four of the film A/epoxy prepregs and then 14 of the CF/epoxy UDprepregs (Fiberdux (phonetic) made by Asahi Composite, 0.2 mm thick)laid in the same direction as the fibers, then four of the film A/epoxyprepregs again were laminated successively using a laminate roll. Thiswas subjected to air-bag autoclave molding under the same conditions amExample 6 to obtain a laminate board of a thickness of about 3 mm. Thelaminate board had a structure of the CF/epoxy layers sandwiched by thefilm A.

Comparative Example 5

A laminate board was obtained by molding by the same conditions asExample 8 using Capton 100H (phonetic) as a film.

Comparative Examples 6 and 7

Ten layers (Comparative Example 6) or 15 layers (Comparative Example 7)of just the CF/epoxy UD prepregs were laminated in the same fiberdirection and molded in an autoclave to give laminate boards ofthicknesses of 2 mm and 3 mm.

The physical properties of the plate molded bodies of Examples 6 and 7and Comparative Examples 4 and 6 are shown in Table 4 and the physicalproperties of the plate bodies of Example 8 and Comparative Examples 5and 7 are shown in Table 5.

All of the plate bodies obtained using film in the examples and thecomparative examples were vastly improved in impact resistance. However,regarding strength and modulus, only the examples of the presentinvention achieved physical properties equal or better than plate bodiesnot using film.

As explained in the general discussion, the physical properties ofcomposite materials are defined by the sum of the physical properties ofthe individual materials constituting the same with consideration to theratios of those materials. Therefore, it is envisioned that the modulusin the reinforcing fiber direction would drop along with a decrease inthe ratio of the fiber-reinforced resin layer and an increase in thefilm layer. Despite this, the plate body of the present inventionmaintains not only the strength, but even the modulus--an unexpectedresult.

Further, regarding a direction orthogonal to the fiber direction, it inclear from the comparative examples that the film elongates tremendouslyand easily deforms when soft. The only film which can give impactresistance without sacrificing the properties of the fiber-reinforcedresin is that meeting the requirements of the present invention.

                                      TABLE 4                                     __________________________________________________________________________    Physical Properties of Board Composed of Film and CF Reinforced Epoxy         Resin Alternately                                                             Laminated                                                                             0° flexure                                                                          90° flexure                                                                          Drop                                               Strength                                                                           Modulus                                                                            Strain                                                                           Strength                                                                           Modulus                                                                            Strain                                                                            impact                                     Film    (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (%)                                                                              (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (%) (J/mm)                                     __________________________________________________________________________    Ex. 6                                                                             20 μm                                                                          138  9140 1.6                                                                              15.4 744  2.3 4.6                                            PPTA                                                                          film                                                                      Ex. 7                                                                             Upilex                                                                            137  9110 1.5                                                                              14.6 727  2.0 4.6                                            20S                                                                       Comp.                                                                             Capton                                                                            128  8910 1.5                                                                              13.6 658  2.2 4.7                                        Ex. 4                                                                             100H                                                                      Comp.                                                                             None                                                                              135  9180 1.6                                                                              11.5 895  1.8 3.0                                        Ex. 6                                                                         __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________    Physical Properties of Board Composed of Film Laminated to Both Sides of      CF Reinforced                                                                 Epoxy Resin                                                                           0° flexure                                                                          90° flexure                                                                          Drop                                               Strength                                                                           Modulus                                                                            Strain                                                                           Strength                                                                           Modulus                                                                            Strain                                                                            impact                                     Film    (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (%)                                                                              (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (%) (J/mm)                                     __________________________________________________________________________    Ex. 8                                                                             20 μm                                                                          128  7300 2.3                                                                              12.5 781  2.5 6.6                                            PPTA                                                                          film                                                                      Comp.                                                                             Capton                                                                            107  5540 2.4                                                                              11.3 698  1.8 6.5                                        Ex. 5                                                                             100H                                                                      Comp.                                                                             None                                                                              128  6900 2.2                                                                              11.5 794  1.6 2.9                                        Ex. 7                                                                         __________________________________________________________________________

EXAMPLE 9

The prepreg composed of the film and PPS obtained in Example 4(hereinafter referred to as the A/PPS) and the UD sheet/PPS prepreg ofcarbon fiber supplied by Phillips Petroleum (tradename: Ryton ACM(phonetic)) were laminated as follows. At first, four sheets of filmA/PPS were laminated, then on top of that nine sheets of Ryton ACM(tradename) (phonetic) were piled so that the fiber axes were inagreement with one another. Then, four shoots of film A/PPS werelaminated to obtain a hard prepreg. This hard prepreg was charged in arectangular flat mold and heatpressed at 350° C. under a pressure of 20kg/cm² for 20 minutes. Then, this was cooled to 50° C. and taken outfrom the mold to obtain a laminated board having a thickness of about 2mm.

EXAMPLE 10

The same hard prepreg as in Example 9 was charged into a mold having acurved face with a radius of curvature of 500 mm and heat-pressed at atemperature of 350° C. and a pressure of 20 kg/cm² for 30 minutes, thencooled to 50° C., then the molded body extracted, to make a dish shapedmolded body.

EXAMPLE 11

The surface of the film B was subjected to a blasting treatment by using180-mesh river sand particles. The film and a carbon fiber UD sheet(APC-2) supplied by ICI impregnated with polyether other ketone(hereinafter referred to as PEEK) were laminated between a pair ofheating rolls heated to 350° C. under a line pressure of 10 kg to makethe prepreg. Compared with APC-2, the prepreg backed with the film hadless cracking along the fiber direction and was extremely easy tohandle.

Ton layers of the prepreg were laminated so that the directions offibers were in agreement with one another. The laminate was charged in amold, heat-pressed at 360° C. under 45 kg/cm² for 20 minutes and cooledto 60° C. to make a laminate board having a thickness of about 2.2 mm.

EXAMPLE 12

A 1420-denier yarn of an aromatic polyamide fiber (Kevlar 49 (phonetic))supplied by Du Pont was set at a creol, and the yarn was introduced intoa 25 percent solution of polyether sulfone supplied by ICI (hereinafterreferred to as PES) in dimethyl acetamide. (hereinafter referred to aDMAc) and impregnated with the solution. The impregnated fiber wascarefully wound at a pitch of 1 mm on a stainless steel drum, at which asilicon release paper had been set in advance, so that no space would beformed between adjacent yarns. The fiber was heated at 100° C. for 3hours while rotating the drum whereby the solvent was removed. At onepoint, the fiber was cut and opened together with the release paper toobtain an aromatic polyamide fiber-reinforced PES having a thickness of0.2 mm.

Separately, film A was coated with a 25 percent solution of PES in DMAcby using a gravure coater and the solvent was removed by heating toobtain a film-like prepreg having a thickness of 40 μm and having onesurface coated with PES. This film was laminated in three layers andnine aromatic polyamide fiber-reinforced PBS sheets were laminated ontop of the same so that the directions of fiber axes were in agreementwith one another, then another three layers of the film-like prepregwere laminated. The assembly was charged in a rectangular flat mold andheatpressed at 320° C. under a pressure of 100 kg/cm² for 20 minutes.This was cooled to 60° C. and the laminated board was taken out from themold. The thickness of the laminated board was about 2 mm.

Comparative Example 8

Ten layers of a carbon fiber UD/PPS (product name Ryton ACM (phonetic))were laminated alone and then molded under the same molding conditionsas Example 9 to obtain a unidirectional laminated board of a thicknessof 2 mm.

Comparative Example 9

Ten layers of a carbon Fiber UD prepreg impregnated with PEEK (productname APC-2) were laminated alone and the same molding conditions as inExample 11 used to obtain a unidirectional laminated board of athickness of 2 mm.

Comparative Example 10

Ten layers of a Kevlar 49 (phonetic) fiber UD prepreg impregnated withthe same PES an used in Example 12 were laminated alone and molded underthe same molding conditions as used in Example 12 to obtain aunidirectional laminated board of a thickness of 2 mm.

The physical properties of the laminated boards obtained in Examples 9,11, and 12 and Comparative Examples 8, 9, and 12 are shown in Table 6.

                                      TABLE 6                                     __________________________________________________________________________    Physical Properties of Board Composed of Film and Fiber-Reinforced            Thermoplastic Resin Bonded Together                                                             Laminate                                                                      structure of                                                                  film and                                                            Rein-     fiber 0° flexure                                                                       90° flexure                                                                      Drop                                      forcing   reinforced                                                                          Strength                                                                           Modulus                                                                            Strength                                                                           Modulus                                                                            impact                            Film    fiber                                                                              Resin                                                                              resin (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (J/mm)                            __________________________________________________________________________    Ex. 9                                                                             20 μm                                                                          Carbon                                                                             PPS  CF/PS layer                                                                         208  12300                                                                              10.8 520  7.8                                   PPTA                                                                              fiber     bonded with                                                     film          film on both                                                                  sides                                                       Ex. 10 μm                                                                          Carbon                                                                             PEEK CF    214  12700                                                                              10.0 770  8.3                               11  PPTA                                                                              fiber     reinforced                                                      (blast        PEEK layer                                                  ed)          and film                                                             film          laminated                                                                     alternately                                                                   one layer                                                                     each                                                        Ex. 20 μm                                                                          Aroma-                                                                             PES  AF    71   6040 6.1  510  7.1                               12  PPTA                                                                              tic       reinforced                                                      film                                                                              poly-     PES layer                                                           amide     bonded on                                                           fiber     both sides                                                                    with film                                                   Comp.                                                                             None                                                                              Carbon                                                                             PPS  --    193  12500                                                                              7.9  780  4.5                               Ex. 8   fiber                                                                 Comp.                                                                             None                                                                              Carbon                                                                             PEEK --    197  12600                                                                              8.5  840  4.8                               Ex. 9   fiber                                                                 Comp.                                                                             None                                                                              Aroma-                                                                             PES  --    67   6100 4.4  510  4.3                               Ex.     tic                                                                   10      poly-                                                                         amide                                                                         fiber                                                                 __________________________________________________________________________

Next, examples of a tubular body will be shown.

EXAMPLE 13

In the same way as in Example 6, the film A and the CF/epoxy UD prepregwere bonded one layer each.

The bonded shoot was wound five times around a stainless steel rod(mold) of a diameter of 10 mm with the fiber axis in the longitudinaldirection to make a prepreg for forming a tubular body.

Next, the prepreg, an wound on the mold, was wrapped with a PET tape(thickness 25 μm) treated for release and was cured for 2 hours in a140° C. hot air circulation typo heating apparatus. The product wastaken out from the heating furnace, the PET tape was removed, and themold was extracted to obtain a laminated tube, i.e., a molded body givena tubular shape by the lamination. The laminated tube had an innerdiameter of 10 mm and an outer diameter of about 12 mm and was composedof a CF prepreg layer and a PPTA film layer alternately laminated.

Comparative Example 11 and 12

Instead of the film A, use was made of Capton 100H (phonetic) andUpilex-20R (phonetic) and laminated tubes with inner diameters of 10 mmand outer diameters of about 12 mm were made by the same method as inExample 13.

The physical proportion of the laminated tubes of Example 13 andComparative Examples 11 and 12 and the CF/epoxy (0° lamination) tubemade in Comparative Example 2 are shown in Table 7.

The results of Table 7 show clearly that the fact that the physicalproperties of the film most the requirements of the prevent inventionhas good effects.

That is, a reinforcement effect in a direction orthogonal to the fibersis obtained, the rigidity of the tube in the same direction isincreased, the flexural properties are remarkably improved, and, also,even the strength in the fiber direction is vastly increased. This isonly obtained in the examples of the present invention.

Further, despite the fact that the impact resistance is a physicalproperty of an opposite tendency from the technical idea of aninterleaf, a large Izod impact strength can be obtained.

EXAMPLE 14

A prepreg comprising the film A coated on one side with an epoxy resin,made in Example 1, was alit in widths of 10 mm to make a tape. A CF.prepreg was wound four times around a stainless steel rod of a diameterof 10 mm so that the fiber axis was in the longitudinal direction. Ontop of this, the tape comprising the film A coated with epoxy was woundunder the same conditions as the method shown in Example 3 using awrapping machine at a pitch of 2.5 mm and a tension of 15 kg/mm², tomake a prepreg comprising eight layers of the film A bonded to theoutside of the CF/epoxy layer.

Next, this prepreg, as wound around the mold, was wrapped with a PETtape (thickness 25 μm) treated for release and cured for 2 hours in a140° C. hot air circulation typo heating apparatus. The product wastaken out from the heating furnace, the PET tape was removed, and thesold was extracted to obtain a laminated tube. This laminated tube hadan inner diameter of 10 mm and an outer diameter of about 12 mm andconsisted of the film layer bonded to the outside of the CF prepreglayer.

Comparative Examples 13 and 14

Instead of the film A, Capton 100H (phonetic) and Upilex-20R (phonetic)were used, epoxy resin (#7714 made by Asahi Fiberlight) was coated underthe same conditions as in Example 1, then the result was slit to make atape of a width of 10 mm. Aside from the use of this tape, the samemethod as in Example 14 was used to make the tubular body.

Table 8 shows the physical properties of the laminated tubes of Examples14 and Comparative Examples 13 and 14 and the CF/epoxy (0° lamination)tube make in Comparative Example 2.

As understood from Table 9 too, the prevent invention is based on anidea completely different from the interleaf art.

That is, the film does not necessarily have to be laminated alternatelywith the fiber-reinforced resin layer. In particular, in a tubular body,the above-mentioned lamination structure can be used effectively.

Further, the face that remarkable effects are obtained by theconstruction of the present invention, including impact resistance isclear from the examples and comparative examples shown in Table 8.

                                      TABLE 7                                     __________________________________________________________________________    Physical Properties of Tubular Body Composed                                  of Film and CF Reinforced Epoxy Resin Laminated Alternately                                 Axial Face                                                                    compressive                                                                         compressive                                                                         Three-point flexure                                               strength                                                                            strength                                                                            Strength                                                                           Modulus                                                                            Izod impact                                      Film   (kg/mm.sup.2)                                                                       (kg/mm.sup.2)                                                                       (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (kg · cm/cm.sup.2)               __________________________________________________________________________    Ex. 13 20 μm PPTA                                                                        59.8  20.9  17.8 1410 240                                              film                                                                   Comp. Ex. 11                                                                         Capton 100H                                                                          38.7  12.5  13.1 1100 232                                       Comp. Ex. 12                                                                         Upilex 20R                                                                           47.2  16.2  14.0 1180 257                                       Comp. Ex. 2                                                                          None   54.9  9.6   10.2 530  154                                       __________________________________________________________________________

                                      TABLE 8                                     __________________________________________________________________________    Physical Properties of Tubular Body Composed of Film                          Laminated to Outer Layer of CF Reinforced Epoxy Resin                                       Axial Face                                                                    compressive                                                                         compressive                                                                         Three-point flexure                                               strength                                                                            strength                                                                            Strength                                                                           Modulus                                                                            Izod impact                                      Film   (kg/mm.sup.2)                                                                       (kg/mm.sup.2)                                                                       (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (kg · cm/cm.sup.2)               __________________________________________________________________________    Ex. 14 20 μm PPTA                                                                        63.9  33.1  18.4 1680 263                                              film                                                                   Comp. Ex. 13                                                                         Capton 100H                                                                          54.6  21.2  14.7 1310 245                                       Comp. Ex. 14                                                                         Upilex 20R                                                                           50.2  23.6  15.0 1290 237                                       Comp. Ex. 2                                                                          None   54.9  9.6   10.2 530  154                                       __________________________________________________________________________

EXAMPLE 15

A carbon fiber UD shoot/PPS (product name Ryton ACM (phonetic))preheated to 150° C. was wound four times around a stainless steel rodshaped mold of a diameter of 10 mm using a sheet rolling apparatus withthe direction of orientation of the carbon fibers coinciding with thelongitudinal direction of the mold. On top of this was wrapped two timesthe 10 mm width tape-like prepreg obtained in Example 4 using a tapingmachine at a pitch of 2.5 mm and a tension of 12 kg. The two ends of thelaminate were firmly gripped by a stainless steel collar, then theassembly was heated in a 350° C. oven for 10 minutes. This was cooled toroom temperature, then the mold was withdrawn and a laminated tube withan inner diameter of 10 mm and an outer diameter of about 12 mm wasobtained.

Comparative Example 15

Instead of the film A, use was made of Upilex-20R (phonetic) and a filmbonded with PPS made by the method of Example 4. The same method as usedin Example 15 was used to obtain a laminated tube of an outer diameterof about 12 mm.

Comparative Example 16

A carbon fiber UD sheet/PPS (product name Ryton ACM (phonetic)) waswound five times about a mold of a stainless steel rod of a diameter of10 mm under the same conditions as in Example 15, the outside waswrapped with a 15 mm width tape of the film A, the assembly was molded,then the film A at the outermost layer of the obtained tubular body waspooled off to make a sample.

The physical properties of the tubular bodies of Example 15 andComparative Examples 15 and 16 are shown in Table 9.

                                      TABLE 9                                     __________________________________________________________________________    Physical Properties of Tubular Body Composed of Film                          and CF Reinforced Thermoplastic Resin Bonded Together                                       Axial Face                                                                    compressive                                                                         compressive                                                                         Three-point flexure                                               strength                                                                            strength                                                                            Strength                                                                           Modulus                                                                            Izod impact                                      Film   (kg/mm.sup.2)                                                                       (kg/mm.sup.2)                                                                       (kg/mm.sup.2)                                                                      (kg/mm.sup.2)                                                                      (kg · cm/cm.sup.2)               __________________________________________________________________________    Ex. 15 20 μm PPTA                                                                        55.4  15.2  14.5 1200 218                                              film                                                                   Comp. Ex. 15                                                                         Capton 100H                                                                          48.1  9.3   11.8 980  191                                       Comp. Ex. 16                                                                         Upilex 20R                                                                           47.1  7.3   9.2  490  157                                       __________________________________________________________________________

Next, an explanation is made of the effects of tension in winding thefilm when winding a film layer on the outer layer of a fiber-reinforcedresin layer to obtain a laminated tubular body, using the followingexample and comparative example.

EXAMPLE 16

A tape-like prepreg obtained by coating the film A on one side withepoxy resin and then slitting it to a width of 10 mm was wound at atension of 8 kg/mm². Otherwise, the same method was used as in Example14 to obtain a tubular body with an inner diameter of 10 mm and an outerdiameter of about 12 mm.

The obtained laminated tube was cut in a direction orthogonal to thelongitudinal direction and the cross-section was viewed by an electronmicroscope. As a result, almost no voids were observed either at thecarbon fiber reinforced resin layer, the film layer, or the interfacebetween the two.

Comparative Example 17

In the same way as in Example 16, the same method as in Example 14 wasused, except that the tension was made 5 kg/mm², to obtain a laminatedtube with an inner diameter of 10 mm and an outer diameter of about 12mm.

The resultant laminated tube showed numerous voids at tho carbon fiberreinforced resin layer and the interface between the carbon fiberreinforced resin layer and the film layer. Further, the interface showedwrinkles, visible to the naked eye, along the direction of arrangementof the carbon fibers. The test piece subjected to an Izod impact testbroke along the wrinkles.

The physical properties of the laminated tubes of Examples 14 and 16 andComparative Example 17 are shown in Table 10.

                                      TABLE 10                                    __________________________________________________________________________    Physical Properties of Tubular Body Composed of                               Film Laminated to Outer Layer of CF Reinforced Epoxy Resin                                   Axial compresive                                                                       Face compressive                                                                       Izod impact                                         Film    strength (kg/mm.sup.2)                                                                 strength (kg/mm.sup.2)                                                                 (kg · cm/cm.sup.2)                  __________________________________________________________________________    Ex. 14 20 μm PPTA film                                                                    63.9     33.1     263                                          Comp. Ex. 16                                                                         Same    60.2     32.8     254                                          Comp. Ex. 17                                                                         Same    56.1     21.8     201                                          __________________________________________________________________________

We claim:
 1. A prepreg comprising at least one layer of a filmcomprising an organic polymer having substantially no melting point andhaving a tensile modulus of 700 kg/mm² or more and a tensile strength of35 kg/mm² or more and at least one layer of a resin, said film and saidresin layer being bonded to each other.
 2. A prepreg according to claim1, wherein said resin layer comprises a thermosetting resin.
 3. Aprepreg according to claim 1, wherein said resin layer comprises athermoplastic resin.
 4. A prepreg according to any one of claims 1 to 3,wherein a plurality of films and a plurality of resin layers arealternately bonded.
 5. A prepreg according to claim 2, wherein saidthermosetting resin is a resin selected from the group comprising anepoxy resin, a polyimide resin, an unsaturated polyester resin, aphenolic rosin, and a polyurethane resin.
 6. A prepreg according toclaim 3, wherein said thermoplastic resin is a resin selected from thegroup comprising a polyphenylene sulfide, a polyether ketone, apolyether ether ketone, a polyether sulfone, a polyether imide, and apolyamide imide.
 7. A prepreg according to claim 1, wherein said film isa film comprising an aromatic polyamide.
 8. A prepreg comprising atleast one layer of a film comprising an organic polymer havingsubstantially no melting point and having a tensile module of 700 kg/mm²or more and a tensile strength of 35 kg/mm² or more and at least onelayer of a fiber-reinforced resin layer, said film and saidfiber-reinforced resin layer being bonded to each other.
 9. A prepregaccording to claim 8, wherein a resin used in the fiber-reinforced resinlayer comprises a thermosetting resin.
 10. A prepreg according to claim8, wherein a resin used in the fiber-reinforced resin layer comprises athermoplastic resin.
 11. A prepreg according to any one of claims 8 to10, wherein at least one layer of film is laminated on an inner layer oran outer layer of at least one laminated fiber-reinforced resin layer.12. A prepreg according to any one of claims 8 to 10, wherein the filmand the fiber-reinforced resin layer are alternately laminated everyother layer or every plurality of layers.
 13. A prepreg according to anyone of claims 8 to 10, wherein a fiber-reinforced layer reinforced by afiber selected from the group comprising carbon fiber, glass fiber,aromatic polyamide fiber, boron fiber, alumina fiber, silicon carbidefiber, polybenzimidazole fiber, and polybenzothiazole fiber is used. 14.A prepreg according to any one of claims 8 to 10, wherein thereinforcing fibers in the fiber-reinforced resin layer consist of aunidirectionally fiber-arranged sheet.
 15. A prepreg according to anyone of claims 8 to 10, wherein the reinforcing fibers of thefiber-reinforced resin layer consist of a sheet selected from a group ofa woven fabric, a knitted fabric, a nonwoven fabric, and a mat sheet.16. A prepreg according to claim 8, wherein a fiber-reinforced resinlayer with a thermosetting resin which is a resin selected from thegroup comprising an epoxy resin, a polyimide resin, an unsaturatedpolyester resin, a phenolic resin, and a polyurethane resin is used. 17.A prepreg according to claim 10, wherein a fiber-reinforced resin layerwith a thermoplastic resin which is a resin selected from the groupcomprising a polyphenylene sulfide, a polyether ketone, a polyetherether ketone, a polyethyl sulfone, a polyether imide, and a polyamideimide is used.
 18. A prepreg according to claim 8, wherein said film ina film comprising an aromatic polyamide.
 19. A plate molded bodycomprising at least one layer of a film and at least one layer of aresin and/or a fiber-reinforced resin layer, wherein said film comprisesan organic polymer having substantially no melting point and has atensile module of 700 kg/mm² or more and a tensile strength of 35 kg/mm²or more, said film, said resin layer, or said fiber-reinforced resinbeing bonded to each other.
 20. A plate molded body according to claim19, wherein a resin used in the resin layer and fiber-reinforced resinlayer comprises a thermosetting resin.
 21. A plate molded body accordingto claim 19, wherein a resin used in the resin layer andfiber-reinforced resin layer consists of a thermoplastic resin.
 22. Aplate molded body according to claim 20, wherein the thermosetting resinis a resin selected from a group comprising an epoxy resin, a polyimideresin, an unsaturated polyester resin, a phenolic resin, and apolyurethane resin.
 23. A plate molded body according to claim 21,wherein the thermoplastic resin is a resin selected from a groupcomprising a polyphenylene sulfide, a polyether ketone, a polyetherother ketone, a polyethyl sulfone, a polyether imide, and a polyamideimide.
 24. A plate molded body according to any one of claims 19 to 21,wherein at least one layer of film is laminated on an inner layer or anouter layer of the at least one laminated fiber-reinforced resin layers.25. A plate molded body according to any one of claims 19 to 21, whereinthe film and the fiber-reinforced resin layer are alternately laminatedevery other layer or every plurality of layers.
 26. A plate molded bodyaccording to any one of claims 19 to 21, wherein a fiber-reinforcedlayer reinforced by a fiber selected from a group comprising carbonfiber, glass fiber, aromatic polyamide fiber, boron fiber, aluminafiber, silicon carbide fiber, polybenzimidazole fiber, andpolybenzothiazole fiber is used.
 27. A plate molded body according toany one of claims 19 to 21, wherein the reinforcing fibers in thefiber-reinforced resin layer consist of a unidirectionallyfiber-arranged sheet.
 28. A plate molded body according to any one ofclaims 19 to 21, wherein the reinforcing fibers of the fiber-reinforcedresin layer consist of a sheet selected from a group of a woven fabric,a knitted fabric, a nonwoven fabric, and a mat sheet.
 29. A plate moldedbody according to claim 19 wherein said film in a film comprising anaromatic polyamide.